Ran boat out of water for ~2min but seems fine? Replace impeller?

[boating347]

Hi all,

I accidently ran engine (2004 Bayliner with MerCruiserAlpha One) in idle above water because I didn't lower the lift enough for about ~2min. Noticed some steam in the back and immediately shut off the engine.

Tested it out today for about an hour and everything still seems to run fine. Temperature gauge staying around ~175 as before.

Should I still have a mechanic take a look? Replace impeller? Being quoted $1-1.5K so prefer to avoid it if I can, but not sure if this could lead to bigger problems.

 

[Bondo]

Ayuh,.... Welcome Aboard,..... 2 minutes is a very long time to spin a dry rubber impeller,.....

Regardless, 2 minutes is an extremely long time to run a wet exhaust, dry,...
I suspect you've burnt the shutters to a crisp, which can cause them to fall down to the bottom of the y-pipe, blockin' the flow of exhaust, 'n water outa the system,.....
Probably burnt the insides of the rubber exhaust couplers too, at the risers, 'n the top of the y-pipe,.....

The Alpha Gen.II has a more durable impeller than the Alpha 1, but personally, I'd install a full kit into the pump,.....

 

[boating347]

Ayuh,.... Welcome Aboard,..... 2 minutes is a very long time to spin a dry rubber impeller,.....

Regardless, 2 minutes is an extremely long time to run a wet exhaust, dry,...
I suspect you've burnt the shutters to a crisp, which can cause them to fall down to the bottom of the y-pipe, blockin' the flow of exhaust, 'n water outa the system,.....
Probably burnt the insides of the rubber exhaust couplers too, at the risers, 'n the top of the y-pipe,.....

The Alpha Gen.II has a more durable impeller than the Alpha 1, but personally, I'd install a full kit into the pump,.....

Thank you Bondo...

Everyone in my area is booked out for weeks. As mentioned, I tested it for an hour and everything seems to be running fine and temperature is staying normal - is it possible that I just got lucky? Or do you think those things you mentioned are hard to tell even if temperature stays normal? Should I look for water buildup?

Thanks again.

 

[Bondo]

- is it possible that I just got lucky?

Donno,..... You asked what could happen,......

They're yer dice to roll, not mine,....

 

[flashback]

Crispy shutters won't effect engine temp. There job is to stop water from surging back into the exhaust. How lucky you are is something no one can predict...

 

[Scott Danforth]

You also burned the flappers out and toasted the rubber hoses

I would spend the $75 on the impeller kit and do the work yourself.

Also, add a $180 bellows kit and alignment tools

Then spend the $200 for rubber bits for the exhaust

 

[JASinIL2006]

I, unfortunately, I am in a similar situation. This Fourth of July, for the first time this year, I fired up the boat.

As I always do, I ran it in the driveway on months before taking it to the river. in my case, I hooked up the hose, and when I opened the ball valve near the muffs, water came out, so I assumed the hose was turned on. It was not; it just had pressure built up from when the ball valve was shut in the spigot had been left on earlier. I ran the engine for about 45 seconds, thinking the water was running. When I noticed, I did not see any water coming out along the sides of the driveway, I quickly shut off the engine.

The exhaust manifolds and rubber elbows, when touched, were warm but not hot. There were no smells or smoke or anything that would be alarming. Nevertheless, I was pretty sure I had fried the new impeller and water pump assembly I installed over the winter. I then tried running it on the muffs for quite a while, to see if it would overheat. It didn’t, but of course it was not under load or anything.

Despite my concerns, we decided to head to the river and see how the boat responded. We ran it near the dock, and got it up to temperature and pushed it a bit, but it held temperature steady. I eventually took it out to the main channel and ran it at wide-open throttle for quite a while, and it held its temperature fine.

I am pretty sure the water pump is OK, because I think when I first started it on the muffs there was enough water pressure to push some water up into that part of the drive. Also, when I installed the new water pump and impeller, I liberally lubed up the inside of the pump housing with 2-4-C.

Other than pulling the rubber exhaust elbows, is there any way for @boating347 and I to know if we fried our shutters?

 

[Scott Danforth]

Exhaust with water is under 220 degrees. Rubber melts at 250 degrees.

Exhaust with out water is 900 or higher

Consider the flappers toast

 

[JASinIL2006]

I'll be interested to hear what you find out, @boating347. I didn't run mine quite as long as you did, a bit less than a minute, but my shutters and rubber bits look fine.